Thread-cutting device for sewing-machines.



No. 742,366. P-ATENTED 00T.'2 '7, 190s.

' J. J. SULLIVAN &'E. B. ALLEN.

THREAD CUTTING DEVICE FOR SEWING MACHINES.

APPLICATION P ILED APR. 23, 1903.

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I No. 742,366. I PATENTEJS 001'. 27,1903. J. J. SULLIVAN & E. B. ALLEN-V THREAD CUTTING DEVICE FOR SEWING MACHINES.

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No. 742,366. PATENTBD 001". 27, 1 03..

J. J; SULLIVAN & E. B. ALLEN.

THREAD CUTTING DEVICE FOR SEWING MACHINES.

APPLICATION FILED APR. 2a, 1903. no MODEL UNITED STATES Patented October27, 1903.

PATENT OFFICE.

JOHN J. SULLIVAN, OF IPSWICH, MASSACHUSETTS, AND EDWARD B. ALLEN,

OF ELIZABETH, NEW JERSEY, ASSIGNORS TO THE SINGER MANUFACTUR- INGCOMPANY, A CORPORATION OF NEVV JERSEY.

'THREAD-CUTTING DEVICE FOR SEWING-MACHINES.

QPECIFICATION forming part of Letters-Patent No. 742,366, dated October27, 1903.

Application filed April 23, 1903- Ii'o all whont it may concern.-

Beit known that we, JOHN J. SULLIVAN, residing at Ipswich, in the countyof Essex, State of Massachusetts, and EDWARD B. ALLEN,

g residing at Elizabeth, in the county of Union and State of New Jersey,both citizens of the United States, have invented certain new and usefulImprovements in Thread-Cutting Devices for Sewing-Machines, of which thefol- 1o lowing is a specification, reference being had therein to theaccompanying drawings.

This invention has for its obj eot to provide an automatic cuttingmechanism for severing the needle-thread close to the work at thecompletion of a group of a predetermined number of stitches, as insewing on buttons, forming bars or tacks, &c. In this improved threadsevering mechanism the knife or cutter is preferably given itsthreadsevering movement by the stored-up power of a compressed springthe retaining device for which is released by connections controlledfrom the stop-motion device of the machine, so that thethread will besevered just as the 5 machine comes to rest.

111 the present invention the thread-cutting device is preferablysupported by or mounted on the presser-foot of the machine, andautomatic means for lifting the presser-foot at 3 the completion of eachgroup of stitches are also provided, The operations of thethreadsevering and presser-foot-lifting mechanisms are, however, sotimed relative to each other that the thread will be out before thepresserfoot is lifted, so as to sever the thread as closely to the workas possible.

The thread-cutting device is preferably so constructed 'as to form anipper which will hold the end of thethread running to the 4 needleuntil after the machine shall have again been started and one or morefasteningstitches forming part of the next group of stitches shall havebeen made in the work, and to insure a proper thread nipping or holdingaction the tension on the needlethread will preferably be released afterthe last stitch of a group of stitches has been properly'tightened bythe take-up, but before the thread-cutter is operated to nip and SerialNo. 153,950. (No model.)

sever the thread, and thus the thread will readily yield, so that enoughthread'will be drawn down by the movable member of the cutting device toenable a suflicient length of thread to extend between the nippingparts, so that there will be no danger of the end of the thread escapingfrom the nipping device when the first stitch of the next group ofstitchesis tightened by the take-up.

In the accompanying drawings, Figures 1 and 2 are opposite sideelevations of a button-sewing machine embodying the invention, thebutton-chute being partly broken away in Fig. 2. Fig. 3 is a front endview of the machine with parts broken away in front of line 3 3, Fig. 2.Figs 4:, 5, and 6 are de-' tail views of the fast and loose pulleys andy the stop-motion cam. Fig. 7 is a detail plan view of the presser-footwith the threadcutter mounted thereon; and Fig. 8, apartlybroken-outside view of the same with the cutter closed. Figs. 9 "and 10 areenlarged cross-sectional views of the presser-foot, illustrative of thethread-cutting and threadnipping operations.

The button-sewing machine in connection with which the present inventionis herein illustrated and which machine is provided with an automaticbutton-feeding mechanism is essentially the same as that shown anddescribed in United States Patent No. 596,020, granted December 21,1897, excepting that the automatic work-feed is in the present instanceomitted, and the machine herein shown is provided with a somewhatdifferent stop-motion device from that shown in said patent, thestop-motion device herein illustrated being similar in its operation tothat of United States Patent No. 541,27 6, granted June 18, 1895. Onlythe parts of the present machine forming a part of or directly connectedwith the thread-cutting mechanism need therefore be herein described.

Referring to the drawings, 12 denotes the button-guiding presser-foot,closely adjacent to the lower end of the button-chute h, extending downfrom the button-hopper g, and from which chute to said presser-foot thebuttons are conveyedby a button-feeder m at the lower end of a verticalrock-shaft, as in said Patent No. 596,020. The presserfoot 12 isprovided with a forwardly-projeeting'part or extension 13, having avertical boss 14, in which is journaled a small shait 15,to the lowerend of which the movable member or blade 16 of the thread cutting andholding device is attached, while the stationary cutting blade or memberis formed on a plate 17, secured to the bottom of the presser-foot, andbetween a portion of which presser-foot and plate 17 the movable bladeor cutter swings. The cutting edge or part of the blade 16 is formed atthe lower side of said blade, while the upper side of the edge of saidblade is suitably rounded or left dull, so as to form, in cooperationwith the closelyadjacent bottom surface of the presser-foot extension13, a thread-nipping device which will nip the thread before it issevered by the closing of the movable member or blade 16 and which willhold the end of the thread running to the needle while the said movablemember or blade remains closed. The movable member or blade 16 swingsacross or closely ad jacent to the vertical path of the needle, so as toengage the thread which runs from the work to the needle when the latteris lifted.

The cutter-carrying shaft is provided atits upper end with an arm 18,jointed to the forward end of a sliding rod 19, the rear end of which issupported by being passed into a hole formed in a part of the frame ofthe machine, said rod being provided with three collars 20, 21, and 22and preferably, also, with a washer 23, between which latter and thecollar is interposed a coil cutter-operating spring 24. The rod 19 isembraced by the forked lower end of a lever 25, between which and thespr ng 24 the washer 23 when used is interposed, or the said springmight impinge directly against said lever if the washer were to beomitted. The lever is provided with a pin or roller-stud 26, entering acam-groove 27 in the intermittingly-rotating cam-cylinder 28, said leverserving to operate the button-feeder, as in the machine shown anddescribed in United States Patent No. 596,020 above referred to.

Pivotally mounted 011 a stud 29, supported by the frame of the machine,is an arm 30, having a finger-piece 31, adapted to enter the notch orspace 32 between the collars and 21, and the collar or sleeve 20 is ofconsiderable length and serves at times as a support or rest for thefinger-piece 31 when the latter is not in the notch or space 32 andbehind the said collar or sleeve 20. Attached to the upper portion ofthe arm bya pivot-screw 3: is a bell-crank lever comprising the arms 34and 35. Passing freely through the upper arm 35 is a sliding rod 36,jointed at its rear end to the upper part of the belt-shiftingstopmotion lever 41, said rod being provided with two collars 38 and 39on opposite sides of the arm 35, and a coil-spring 40 is interposedbetween said collar 39 and said arm.

The cam-cylinder 28 is intermittingly r0- tated by a lever-dog 41,operating in the manner fully described in United States PatentNo.541,840, granted July 2, 1895, and having a horizontal reciprocatingmovement transverse to the said cylinder, as well as a slight swingingmovement on a pivot-screw 42, which attaches a block 43 to saidlever-dog, so that said block reciprocates horizontally with saidleverdog. The said. block 43 is guided in its horizontal movements in aslot formed in the arm of the machine, and the arm 35 is provided with apin 44, which at times is brought into the pathof movement of saidblock.

The driving-shaft 45 of the machine is provided with the loose pulley 46and the fast pulley 47, from one to the other of which apower-transmittin g belt will be moved by the belt-shifter 48, carriedby the stop-motion lever 41. Mounted loosely on a sleeve of the fastpulley is a cam 37, having a notch 49, said cam being yieldinglyconnected with said pulley, so as normally to rotate therewith throughthe springs 50 and 51 on opposite sides of a block 52 on a pin 53,passing through a slot in the face of said fast pulley adjacent to saidcam. The springs 50 and 51 are separated from each other by a radial pin54,1'igidly mounted in the fast pulley, said springs being of unequalstrength, the spring 51 being the lightest. The stop-motion lever isprovided with a vertically-movable rod or plunger 55, yieldingly forcedupward by a spring 56, the upperend of which bears against a collar 57,fast on said rod.

The presser bar 62 is forced yieldingly downward on the work in theusual manner by a spring 58, surrounding said bar, and to the said baris attached a block 59, having a lip to be engaged by the forward end ofa lifting-lever 61, provided at its rear end with an ear 63, throughwhich loosely passes a rod 64, jointed at its lower end to the forwardend of a lever 65, pivoted to the frame of the machine, and provided atits rear end with a springpressed latch or catch 66. The rod 64 isprovided at its upper end with a collar 67, between which and the car 63is interposed a stiff coil-spring 68.

W hen the machine is running and a group of stitches is being formed,the stop-motion lever is held in the position denoted bydotted lines inFig. 1 by the catch-lever 69, as in said Patent No. 596,020, saidcatch-lever being tripped to release said stop-motion lever and allow itto assume the position shown in full lines in Fig. 1 by a lug orprojection on the cam-cylinder 28, as in said patent. Also when themachine is running the cutting device will be open, as in Fig. 7, themovable cuttingblade being at this time held in its open position by thefinger-piece 31 against the stress of the blade-closin g orcutter-operating spring 24, said finger-piece at this time resting inthe notch or space 32 and behind the sleeve or long collar 20. Also whenthe machine is crank lever 34 35 and holds said leverin the positionshown in dotted lines in Fig. l, and in which position the pin 44 insaid arm 35 is in a forward position out of the range of movement of thehorizontallyreciprocating block 43. Thus wh en the stop-motion lever 41is moved toward stopping position the collar 38 is withdrawn from thearm 35, and the spring 40 will move the said arm rearward,

bringing the pin 44 against the block 43, so that when said block nextmoves inward the said spring will move said arm 35 still fartherrearward and bring the said pin directly in the path of movement of thesaid block. With the stop-motion lever in stopping position the cam 37forces the rod or plunger 55 downward against the stress of itslifting-spring 56, and as said rod or plunger is thus moved downward thecollar 57, carried thereby, moves below the hook of the spring-pressedcatch or latch 66 on the lever 65. As the full portion of the cam 37passes the upper end of the rod or plunger 55 said end is forced by thespring 56 into the notch 49 of said cam, thus arresting the movement ofthe latter; but the yielding cushioning connection of said cam with thefast pulley 47 afforded by the springs 50 and 51 permits a slightadditional rotation or movement of said pulley and of the driving-shaftagainst the stress of the spring 51; but this is resisted by the spring50, the recoil of which serves to move the driving -shaft backward farenough to cause the block 43 to have at that instant an outward movementagainst the pin 44, so as to move the arm 30 and lift the finger-piece31, carried thereby, out of the notch or space 32, thus allowing thecoilspring 24 to move the sliding rod 19 rearward to close the cuttingdevice, so as to nip and sever the needle-thread. Then the rod orplunger 55 moves upward to enter the notch 49 in the cam 37, the rearend of the lever is also moved upward by the catch or latch 66, now inengagement with the collar 57 on said rod or plunger, and this upwardmovement of the rear end of said lever moves the forward end of saidlever downward, thus compressing the presser -bar lifting spring 68,which would now operate the lifting-lever 61 but for the fact that thelifting stress of said spring is momentarily resisted by a latchlever69, having near its upper end a ShOll]: der 71, which is beneath alaterally-projecting lug at or near the rear end of the lever 61; butafter the sliding rod 19 has been moved rearward far enough to cause themovable member 16 of the thread-cutting device to nip and sever theneedle-thread the rear end of said rod strikes against the lower arm ofthe latch-lever 69 and moves said latchlever against the stress of itsholding-spring 7 2, so as to disengage the upper end of said latch-leverfrom the holding-lug 7 O on the presser-liftin g lever,and thus permitthe compressed spring 68 to raise the presser-foot from the work. Thusthe needle-thread will be severed close to the work, and after this hasbeen done the presser-foot is automatically lifted to release fthe work.WVhen the machine is first started for the next stitching operation,

the cutting device remains closed until after one or more (preferablytwo or three) fastening-stitches have been made in the work, and thelower end of the lever 25 will then move forward in contact with thecollar 21, so as to move the sliding rod 19 forward, and thus open thecutting device in readiness for the next cutting operation and alsorelease the thread held nipped in the said cutting device, thebutton-feeder m being in the present machine operated to carry a buttonto sewing position simultaneously with the opening of the cuttingdevice.

When the upper arm of the bell-crank lever 34 35 is moved rearward bythe compressed spring 40 on the rod 36, the forward end of the lower armof said bell-crank lever is lifted to bring said forward end, or a smalllug or button 7 3 carried thereby, against a releasingarm 74 of thetension device 75, through which passes the thread running to thetake-up lever 76, and thence to the needle. Thus the tension on theneedle-thread will be released, so that when the movable member or blade16 of the thread nipping and severing device is closed it freely drawsdown sufficient thread, so that an end of suitable length will be heldby the thread-nipper, and thus any danger of the accidental escape ofthe end of the thread from the thread-nipper at the commencement of thenext stitch-forming operation will be avoided.

Having thus described our invention, we claim and desire to secure byLetters Patent 1. In a sewing machine, the combination with apresser-foot, and a thread-severing and a thread-holding device mountedin said presser-foot, of automatic means for closing said threadsevering and holding device, to cause it to sever and nip the thread,and an automatic presser-foot lifting mechanism timed to raise thepresser-foot and release the work after the thread has been severed andwhile it is still held by the severing and nipping device. 2. In asewing-machine, the combination with a presser-foot, and athread-severing and a thread-holding device mounted in said-presser-foot, of automatic means for closing and opening said threadsevering and holding device, to cause it to sever, nip and release thethread, and an automatic presserfoot-lifting mechanism timed to raisethe presser-foot and release the work after the thread has been severedand while it is still held by the severing and nipping device.

3. In a sewing-machine, the combination with a presser-foot, and. athread-severing 'and a thread-holding device mounted in saidpresser-foot, of automatic means for closing said thread severing andholding device, to

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cause it to sever and nip the thread, an automatic presser-foot-liftingmechanism timed to raise the presser-foot and release the work after thethread has been severed and while it is still held by the severing and.nipping device, and an automatic stop-motion mechanism by which, after agroup of a predetermined number of stitches has been formed, the machinewill be stopped.

4. In a sewing-machine, the combination with a Presser-foot, and athread-severing and a thread-holding device mounted in saidpresser-foot, of automatic means for closing and opening said threadsevering and hold ing device, to cause it to sever, nip and release thethread, an automatic presser-footlifting mechanism timed to raise thepresserfoot and release the work after the thread has been severed andwhile it is still held by the severing and nipping device, and anautomatic stop-motion mechanism by which, after a group of apredetermined number of stitches has been formed the machine will bestopped.

5. In a sewing-machine, the combination with a thread severing andholding device, and an operating mechanism therefor, of a presser-footand an automatic presser-footlifting mechanism the timing of which iscontrolled by said operating mechanism for said severing and holdingdevice, so that after the latter has been closed, to sever and nip thethread, the said presser-foot will be automatically lifted.

6. In a sewing-machine, the combination with a presser-foot, of a threadsevering and holding device mounted thereon, a reciprocating part forclosing and opening the movable member of the said severing and holdingdevice, and an automatic presser-foot-lifting mechanism comprising acontrolling device to prevent the presser-foot from being raised andwhich controlling device is tripped by said reciprocating part and afterthe latter has closed the severing device to sever and nip the thread.

'7. In a sewing-machine, the combination with a thread severing andholding device comprising a movable thread-severing member and astationary member between which and said movable thread-severing memberthe thread is nipped and held, of a tension device through which thethread to be severed and held passes, and a tension-releasing deviceactuated to release the tension on the thread before the thread severingand holding device is closed, so that thread may be freely drawn to thesaid thread severing and holding device by the said movable member.

8. In a sewing-machine, the combination with a thread severing andholding device mounted on the presser-foot of the machine and comprisinga movable thread severing and nipping member, of a tension devicethrough which the thread to be severed and held passes, atension-releasing device actuated to release the tension on the threadbefore the thread severing and holding device is closed, so that threadmay be freely drawn to the said thread severing and holding device bythe said movable member, and an automatic presser-foot-lifting mechanismtimed to lift the presser-foot after the thread has been severed.

9. In a button-sewing machine, the combination with an automaticbuttonfeeding mechanism, of an automatic thread severing and holdingdevice arranged above the worksupport, and an automatictension-releasing device by which the tension on the thread running tothe said severing and holding device is released before the said threadsevering and holding device is closed.

10. In a button-sewing machine, the combination with an automatic buttonfeeding mechanism, of a presser-foot, an automatic thread severing andholding device mounted on said presser-foot and an automaticpresserfoot-lifting mechanism timed to lift said presser-foot after thesaid thread severing and holding device has been closed.

11. In abutton-sewing machine, the combination with an automatic button-feeding mechanism, of a presser-foot, an automatic thread severing andholding device mounted on said presser-foot, an automaticpresserfoot-lifting mechanism timed to lift said presser-foot after thesaid thread severing and holding device has been closed, and atension-releasing device timed to release the tension on the threadrunning to said severing and holding device before the latter is closed.

In testimony whereof we affix our signatures in presence of twowitnesses.

J OIIN J. SULLIVAN. EDIVARD I3. ALLEN.

\Vitnesses:

II. J. MILLER, II. A. KORNEMANN.

